Technique for matching a query to a portion of media

ABSTRACT

A method for matching a query to a portion of media, includes receiving a query relating to media of interest and searching, based upon the query, an index of annotations. Each of the annotations represents a respective item of available media and includes a plurality of annotation values. Each of the plurality of annotation values represents a portion of the represented item of available media. By matching the query to an annotation value within the index, the start time of a media stream forming the portion of the item of available media represented by the identified annotation value can be identified. The identified media stream start time can then be provided in response to the query, allowing the appropriate portion of the applicable item of available media to be directly accessed.

This application is a continuation of pending application Ser. No.09/037,957, filed on Mar. 11, 1998.

FIELD OF THE INVENTION

The present invention relates generally to the field of multimedia and,more particularly, to a technique for matching a query to a portion ofmedia.

BACKGROUND OF THE INVENTION

There are a large number of organizations that presently havesubstantial amounts of audio, video, and image content in analog form.Many of these organizations are currently moving toward putting suchmultimedia content into digital form in order to save costs in the areasof data storage and retrieval. That is, similar to other types of data,multimedia content can be easily stored on and retrieved from relativelyinexpensive digital storage devices.

The migration of multimedia content from analog form to digital formalso provides an organization with the ability to store, search, browse,and retrieve digitized multimedia content from distributed sites. Thatis, an organization having a number of distributed offices can store,search, browse, and retrieve digitized multimedia content from acentralized storage facility over a proprietary intranet computernetwork such as, for example, a local area network (LAN), or a publicinternet computer network such as, for example, the world wide web.

Furthermore, the multimedia content itself may be distributed. That is,an organization that is global in nature may have a number ofdistributed permanent archival storage locations where digitizedmultimedia content is permanently stored, or a number of distributedtemporary storage locations where digitized multimedia content that isassociated with work in progress is temporarily stored. Similar toabove, such an organization could also store, search, browse, andretrieve digitized multimedia content from the distributed storagelocations over a proprietary intranet computer network or a publicinternet computer network.

Additionally, an organization may want other entities located outside ofthe organization to be able to search, browse, and retrieve digitizedmultimedia content stored and maintained within the organization. Forexample, an organization may want to sell multimedia content to anoutside entity, which may then use the purchased multimedia content forsome purpose such as, for example, a news broadcast. Similar to above,the outside entity could search, browse, and retrieve digitizedmultimedia content from a storage facility within the organization overa proprietary intranet computer network or a public internet computernetwork.

However, despite the above-described benefits associated with digitizedmultimedia content, organizations presently have little or no means ofsearching within multimedia content, organizing information aboutmultimedia content, and delivering multimedia content in a ubiquitousmanner. That is, there are presently little or no means for searchinginside streams of multimedia content (e.g., audio/video streams), addingmeta-information to multimedia content (i.e., annotating multimediacontent) for purposes of indexing within multimedia content, andproviding universal access to indexed multimedia content over a varietyof connection speeds and on a variety of client platforms. Accordingly,it would be desirable to provide a technique for organizing distributedmultimedia content and for searching, browsing, and retrieving suchorganized distributed multimedia content in an efficient andcost-effective manner so as to overcome the above-described shortcomingsof the prior art.

OBJECTS OF THE INVENTION

The primary object of the present invention is to provide a techniquefor matching a query to a slice of media.

The above-stated primary object, as well as other objects, features, andadvantages, of the present invention.

According to the present invention, a query, for example received over anetwork such as the Internet, is matched to a portion of media bysearching an index of annotations. Each of the annotations correspondsto a respective item, such as a film or tape clip, of an available audioor video media, and includes multiple annotation values, e.g. words orother text. Each of the annotation values corresponds to a portion ofthe applicable item, such as a segment of the film or tape clip. Bymatching the query to an annotation value within the index, anannotation value and its associated start time are identified. Theassociated start time is the start time of a media stream forming theportion of the item of available media corresponding to the identifiedannotation value. A signal representing the identified media streamstart time can be generated and transmitted, for example over theInternet or other network, in response to the query.

Beneficially, a meta database having a plurality of start times is alsosearched. Each of the plurality of start times has an associated endtime, which could be in the form of a delta value. By matching theidentified media stream start time with a start time within theplurality of start times the associated end time can be identified. Theassociated end time is the end time of the media stream. A signalrepresenting the identified media stream end time can be generated andtransmitted, for example over the Internet or other network, in responseto the query.

Each of the plurality of start times in the meta database may also oralternatively include an associated address, such as a URL, of the itemof available media corresponding to the identified annotation value.Hence, the meta database may additionally or alternatively be searchedto identify the item address associated with the identified matchingstart time. The associated address is the address of the item ofavailable media corresponding to the identified annotation value. Asignal representing the identified address can be generated andtransmitted, for example over the Internet or other network, in responseto the query. The identified media stream start and/or end times mayadvantageously be provided as an extension of the URL or other address.

In accordance with other aspects of the invention, each of the pluralityof annotation values may correspond to more than one portion of the itemof available media. If the identified annotation value corresponds tomultiple portions of the item of available media, media stream starttimes of respective media streams forming the multiple portions of theitem are identified, and transmitted in response to the query.

The searching may be performed by one or more computer processors. Forexample, the annotation index may be stored on a memory and searched atone location on the network by one processor and the meta database couldbe stored on another memory and searched by another processor at adifferent location on the network. Preferably, the processor associatedwith the index receives the information gathered in the search of themeta database and transmits the response to the query via the network tothe applicable user. The invention is typically implemented usingcomputer programming stored on electronic, magnetic, optical or othermedia. The stored computer programming is configured to be readable fromthe media by one or more computers to thereby cause the computer(s) tooperate in the manner described above.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to facilitate a fuller understanding of the present invention,reference is now made to the appended drawings. These drawings shouldnot be construed as limiting the present invention, but are intended tobe exemplary only.

FIG. 1A is a schematic diagram of a first embodiment of a system fororganizing distributed multimedia content and for searching, browsing,and retrieving such organized distributed multimedia content inaccordance with the present invention.

FIG. 1B is a schematic diagram of a second embodiment of a system fororganizing distributed multimedia content and for searching, browsing,and retrieving such organized distributed multimedia content inaccordance with the present invention.

FIG. 2 is a flowchart diagram detailing the processing steps of anencoder client in accordance with the present invention.

FIG. 3 is a flowchart diagram detailing the processing steps of atranscoder client in accordance with the present invention.

FIG. 4 is a flowchart diagram of an encoding process for use in anencoder and transcoder in accordance with the present invention.

FIG. 5 shows the file structure for a file that is stored in a mediadatabase containing a digital representation of audio/video data inaccordance with the present invention.

FIG. 6 shows an annotation structure for an object in accordance withthe present invention.

FIG. 7 shows the structure of an object database of a meta database inaccordance with the present invention.

FIG. 8 shows an object table of a meta database in accordance with thepresent invention.

FIG. 9 shows a representation table of a meta database in accordancewith the present invention.

FIG. 10 shows an annotation table of a meta database in accordance withthe present invention.

FIG. 11 shows an exemplary HTML query page in accordance with thepresent invention.

FIG. 12 shows an exemplary HTML results page in accordance with thepresent invention.

FIG. 13 shows an exemplary HTML matches page in accordance with thepresent invention.

FIG. 14 shows an exemplary HTML more context page in accordance with thepresent invention.

FIG. 15 is a schematic diagram of a processing device for facilitatingthe implementation of input data processing and output data generationin the components of the present invention.

DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT

Referring to FIG. 1A, there is shown a schematic diagram of a firstembodiment of a system 10A for organizing distributed multimedia contentand for searching, browsing, and retrieving such organized distributedmultimedia content in accordance with the present invention. The system10A comprises a user 11, raw audio/video data 12, at least one encoderclient 14, at least one transcoder client 16, at least one annotationclient 18, at least one browser client 20, a media database 22, a mediadatabase server 24, a meta database 26, a meta database server(librarian) 28, an index database 30, an index database server 32, and acommunication network 34 for allowing communication between all of theabove-identified components which are connected thereto. Thecommunication network 34 as described herein is an internet protocol(IP) network using hypertext transfer protocol (HTTP) messaging so as toexploit the distributed nature of the world wide web (WWW). However, thesystem 10A may be implemented using other types of network protocols,and many of the above-identified components may be grouped together in asingle processing device so as to altogether eliminate the need forinter- or intra-network communications between these grouped components.

In brief overview, the system 10A operates such that the raw audio/videodata 12 is provided to the encoder client 14 for processing by theencoder client 14. Before processing the raw audio/video data 12, theencoder client 14 sends a message over the communication network 34 tothe librarian 28 requesting the creation of an object in the metadatabase 26 corresponding to the raw audio/video data 12. The librarian28 processes the message from the encoder client 14 by creating anobject in the meta database 26 corresponding to the raw audio/video data12 and assigns the object an object identification number, as describedin more detail below. The librarian 28 then sends a message, includingthe object identification number associated with the raw audio/videodata 12, over the communication network 34 to the encoder client 14notifying the encoder client 14 of the creation of the object in themeta database 26 corresponding to the raw audio/video data 12.

Upon receipt of the notification from the librarian 28, the encoderclient 14 digitally encodes the raw audio/video data 12 so as togenerate a first digital representation of the raw audio/video data 12,as described in more detail below. The encoder client 14 then sends amessage, including the first digital representation of the rawaudio/video data 12, over the communication network 34 to the mediadatabase server 24 requesting that the media database server 24 storethe first digital representation of the raw audio/video data 12 in themedia database 22. The media database server 24 processes the messagefrom the encoder client 14 by first checking to see if space isavailable in the media database 22 to store the first digitalrepresentation of the raw audio/video data 12 in the media database 22.If space is not available in the media database 22, the media databaseserver 24 denies the request to store the first digital representationof the raw audio/video data 12 in the media database 22. However, ifspace is available in the media database 22, the media database server24 stores the first digital representation of the raw audio/video data12 at a location in the media database 22 and assigns the location afirst universal resource locator (URL). The media database server 24then sends a message, including the first URL, over the communicationnetwork 34 to the encoder client 14 notifying the encoder client 14 ofthe storage of the first digital representation of the raw audio/videodata 12 in the media database 22.

Upon receipt of the notification from the media database server 24, theencoder client 14 sends a message, including the object identificationnumber associated with the raw audio/video data 12 and the first URL,over the communication network 34 to the librarian 28 notifying thelibrarian 28 of the digital encoding of the raw audio/video data 12 intothe first digital representation of the raw audio/video data 12, and thestoring of the first digital representation of the raw audio/video data12 in the media database 22 at the location identified by the first URL.The librarian 28 processes the message from the encoder client 14 bystoring the first URL in the meta database 26 along with the objectidentification number associated with the raw audio/video data 12, asdescribed in more detail below.

The transcoder client 16 periodically sends messages to the librarian 28requesting work from the librarian 28. The librarian 28 processes such amessage from the transcoder client 16 by first checking to see if thereare any objects in the meta database 26 that have corresponding digitalrepresentations which have not been processed by the transcoder client16. If there are no objects in the meta database 26 that havecorresponding digital representations which have not been processed bythe transcoder client 16, then the librarian 28 denies the work request.However, if there are objects in the meta database 26 that havecorresponding digital representations which have not been processed bythe transcoder client 16, such as, for example, the first digitalrepresentation of the raw audio/video data 12, then the librarian 28sends a message, including the object identification number associatedwith the raw audio/video data 12 and the first URL, over thecommunication network 34 to the transcoder client 16, thereby notifyingthe transcoder client 16 that the first digital representation of theraw audio/video data 12 has not been processed by the transcoder client16.

Upon receipt of the notification from the librarian 28, the transcoderclient 16 sends a message, including the first URL, over thecommunication network 34 to the media database server 24 requesting thatthe media database server 24 send a copy of the first digitalrepresentation of the raw audio/video data 12 to the transcoder client16 for processing by the transcoder client 16. The media database server24 processes the message from the transcoder client 16 by sending amessage, including a copy of the first digital representation of the rawaudio/video data 12, over the communication network 34 to the transcoderclient 16 for processing by the transcoder client 16. The transcoderclient 16 processes the copy of the first digital representation of theraw audio/video data 12 such that a second digital representation of theraw audio/video data 12 is generated, as described in more detail below.

After the transcoder client 16 has processed the copy of the firstdigital representation of the raw audio/video data 12, and generated thesecond digital representation of the raw audio/video data 12, thetranscoder client 16 sends a message, including the second digitalrepresentation of the raw audio/video data 12, over the communicationnetwork 34 to the media database server 24 requesting that the mediadatabase server 24 store the second digital representation of the rawaudio/video data 12 in the media database 22. The media database server24 processes the message from the transcoder client 16 by first checkingto see if space is available in the media database 22 to store thesecond digital representation of the raw audio/video data 12 in themedia database 22. If space is not available in the media database 22,the media database server 24 denies the request to store the seconddigital representation of the raw audio/video data 12 in the mediadatabase 22. However, if space is available in the media database 22,the media database server 24 stores the second digital representation ofthe raw audio/video data 12 at a location in the media database 22 andassigns the location a second URL. The media database server 24 thensends a message, including the second URL, over the communicationnetwork 34 to the transcoder client 16 notifying the transcoder client16 of the storing of the second digital representation of the rawaudio/video data 12 in the media database 22 at the location identifiedby the second URL.

Upon receipt of the notification from the media database server 24, thetranscoder client 16 sends a message, including the objectidentification number associated with the raw audio/video data 12 andthe second URL, over the communication network 34 to the librarian 28notifying the librarian 28 of the transcoding of the first digitalrepresentation of the raw audio/video data 12 into the second digitalrepresentation of the raw audio/video data 12, and the storing of thesecond digital representation of the raw audio/video data 12 in themedia database 22 at the location identified by the second URL. Thelibrarian 28 processes the message from the transcoder client 16 bystoring the second URL in the meta database 26 along with the objectidentification number associated with the raw audio/video data 12, asdescribed in more detail below.

The annotation client 18 periodically sends messages to the librarian 28requesting work from the librarian 28. The librarian 28 processes such amessage from the annotation client 18 by first checking to see if thereare any objects in the meta database 26 that have corresponding digitalrepresentations which have not been processed by the annotation client18. If there are no objects in the meta database 26 that havecorresponding digital representations which have not been processed bythe annotation client 18, then the librarian 28 denies the work request.However, if there are objects in the meta database 26 that havecorresponding digital representations which have not been processed bythe annotation client 18, such as, for example, the first digitalrepresentation of the raw audio/video data 12, then the librarian 28sends a message, including the object identification number associatedwith the raw audio/video data 12 and the first URL, over thecommunication network 34 to the annotation client 18, thereby notifyingthe annotation client 18 that the first digital representation of theraw audio/video data 12 has not been processed by the annotation client18.

Upon receipt of the notification from the librarian 28, the annotationclient 18 sends a message, including the first URL, over thecommunication network 34 to the media database server 24 requesting thatthe media database server 24 send a copy of the first digitalrepresentation of the raw audio/video data 12 to the annotation client18 for processing by the annotation client 18. The media database server24 processes the message from the annotation client 18 by sending amessage, including a copy of the first digital representation of the rawaudio/video data 12, over the communication network 34 to the annotationclient 18 for processing by the annotation client 18. The annotationclient 18 processes the copy of the first digital representation of theraw audio/video data 12 so as to generate annotations for the object inthe meta database 26 corresponding to the raw audio/video data 12, asdescribed in more detail below.

After the annotation client 18 has processed the copy of the firstdigital representation of the raw audio/video data 12, and generated theannotations for the object in the meta database corresponding to the rawaudio/video data 12, the annotation client 18 sends a message, includingthe object identification number associated with the raw audio/videodata 12 and the annotations that were generated for the object in themeta database corresponding to the raw audio/video data 12, over thecommunication network 34 to the librarian 28 notifying the librarian 28of the generating of the annotations for the object in the meta databasecorresponding to the raw audio/video data 12. The librarian 28 processesthe message from the annotation client 18 by storing the annotationsthat were generated for the object in the meta database corresponding tothe raw audio/video data 12 in the meta database 26 along with theobject identification number associated with the raw audio/video data12, as described in more detail below.

The index database server 32 periodically sends messages to thelibrarian 28 requesting a list of object identification numbers from thelibrarian 28 which correspond to objects that have been created in themeta database 26. The librarian 28 processes such a message from theindex database server 32 by sending a message, including a list ofobject identification numbers corresponding to objects that have beencreated in the meta database 26, over the communication network 34 tothe index database server 32 for processing by the index database server32. The index database server 32 processes the message from thelibrarian 28 by sending a message, including, for example, the objectidentification number associated with the raw audio/video data 12, overthe communication network 34 to the librarian 28 requesting that thelibrarian 28 send a copy of the annotations that were generated for theobject in the meta database corresponding to the raw audio/video data12, such as, for example, the annotations that were generated for theobject in the meta database corresponding to the raw audio/video data12. The librarian 28 processes the message from the index databaseserver 32 by sending a message, including the annotations that weregenerated for the object in the meta database corresponding to the rawaudio/video data 12, over the communication network 34 to the indexdatabase server 32 for processing by the index database server 32. Theindex database server 32 processes the message from the librarian 28 bystoring the annotations that were generated for the object in the metadatabase corresponding to the raw audio/video data 12 in the indexdatabase 30 along with, or with reference to, the object identificationnumber associated with the raw audio/video data 12, as described in moredetail below.

The browser client 20 allows the user 11 to interface with the indexdatabase server 32 such that the user 11 is allowed to search, browse,and retrieve all or a portion of a digital representation such as, forexample, the first digital representation of the raw audio/video data12. The browser client 20 sends a message, initiated by the user 11,over the communication network 34 to the index database server 32requesting a search of the index database 30. The index database server32 processes the message from the browser client 20 by sending amessage, including a hypertext markup language (HTML) query page, to thebrowser client 20 for presentation to the user 11. The browser client 20then presents the HTML query page to the user 11. The HTML query page issuch that it allows the user 11 to enter textual and boolean queries.

The user 11 enters a query through the HTML query page and the browserclient 20 sends a message, including the query, over the communicationnetwork 34 to the index database server 32 for processing by the indexdatabase server 32. The index database server 32 processes the messagefrom the browser client 20 by searching the index database 30 forannotations which match the query, and obtaining the objectidentification number associated with each matching annotation, asdescribed in more detail below. The index database server 32 then sendsa message, including each matching annotation and the objectidentification number associated with each matching annotation, over thecommunication network 34 to the librarian 28 requesting that thelibrarian 28 provide the URL of the digital representation from whicheach matching annotation was generated such as, for example, the firstURL. The librarian 28 processes the message from the index databaseserver 32 by searching the meta database 26 for the URL of the digitalrepresentation from which each matching annotation was generated, asdescribed in more detail below. The librarian 28 then sends a message,including each matching annotation, the URL of the digitalrepresentation from which each matching annotation was generated, andthe object identification number associated with each matchingannotation, over the communication network 34 to the index databaseserver 32 for processing by the index database server 32.

The index database server 32 processes the message from the librarian 28by building an HTML results page for presentation to the user 11. Theindex database server 32 builds the HTML results page by creating animage or an icon corresponding to the URL of the digital representationfrom which each matching annotation was generated. That is, each imageor icon is hyperlinked to a function or script which allows the user 11to browse and/or retrieve all or a portion of a corresponding digitalrepresentation such as, for example, the first digital representation ofthe raw audio/video data 12. Once the HTML results page has been built,the index database server 32 sends a message, including the HTML resultspage, to the browser client 20 for presentation to the user 11. Thebrowser client 20 then presents the HTML results page to the user 11 sothat the user 11 can select one of the images or icons so as to browseand/or retrieve all or a portion of a corresponding digitalrepresentation such as, for example, the first digital representation ofthe raw audio/video data 12.

In order to browse and/or retrieve all or a portion of a digitalrepresentation such as, for example, the first digital representation ofthe raw audio/video data 12, a method for efficiently delivering slicesof media from large media streams is required. For real-time mediastreams such as video or audio tracks, URLs must be extended to specifynot only a desired file but also the starting and ending time that is tobe returned to a requesting entity. This can be done by attaching one ormore server extensions to a standard HTTP server such that an URL of theform:

http://www.digital.com/movie.mpg?st=1:00:00.00?et=1:00:05.00

will cause a server extension attached to the standard HTTP server, inthis case named “www.digital.com”, to fetch and stream the movingpictures expert group (MPEG) stream for “movie” starting at time code“1:00:00.00” and ending at time code “1:00:05.00”. In the system 10Ashown in FIG. 1A, the media database server 24 has a server extensionfor performing these fetch and stream operations.

The generalization of the above-described technique is to provide a wellknown method for selecting a portion of a digital representation usingspecified file parameters. The URL can be of the form:

 http://server/file_name?file_parameter

Such a generalization allows the file_parameter field to specify aformat in which a digital representation will be supplied. Thus, thetranscoding of a digital representation into another format can berequested of the media database server 24 by so indicating in thefile_parameter field. For example, to extract MPEG audio from an MPEGsystem stream, the media database server 24 will receive an URL in theabove-described form from a requesting entity. The media database server24 determines the appropriate server extension based upon what isindicated in the file_parameter field. The media database server 24 thenpasses the file_name and the file_parameter to the appropriate serverextension. The server extension then generates a multipurpose internetmail extension (MIME) header which is sent to the requesting entitythrough the media database server 24. The server extension then opensthe file indicated in the file_name field and strips-off any headerinformation that may be contained at the beginning of the file. Thefile_parameter identifies the portion of the file that was requested bythe requesting entity, and optionally drives transcoding or sub-streamextraction. The server extension then generates a new header andprovides the requested file portion to the media database server 24,which then sends the requested file portion to the requesting entity.

Although this generalized technique is feasible, the efficiency of theapproach depends upon the implementation of the server extension foreach type of representation. For video sequence representation typessuch as MPEG and/or H.263, the present invention allows for the storingof extra information alongside a primary video stream. This makes itpossible to return a portion of the primary video stream to a requestingentity from almost any location within the primary video stream withoutincreasing the network bit rate requirements, as described below.

Efficient image sequence encoding for video sequences exploits theredundancy that occurs in a sequence of frames. In a video sequence fora single scene, only a few objects will move from one frame to the next.This means that by applying motion compensation it is possible topredict a current image in the video sequence from a previous image.Furthermore, this implies that the current image can be reconstructedfrom a previously transmitted image if all that is sent to a requestingentity are motion vectors and a difference between a predicted image andan actual image. This technique is well known and is termed predictiveencoding.

The predictive encoding technique can be extended to make predictionsabout a current image based upon any prior image and any future image.However, the details of such an extension are not necessary tounderstanding the methodology of the present invention. What isnecessary to understanding the methodology of the present invention, isthat an image frame which has been encoded independently of any otherframe is defined as an intra or I-frame, and an image frame which hasbeen encoded based upon a previous frame is defined as a predicted orP-frame.

An important extension of the above discussion, is that frames aregenerally encoded by breaking them into fix sized blocks. Each block canthen be separately encoded by producing an I-block, or each block can beencoded using previous blocks by producing a P-block. Transmitted framescan then consist of a mixture of I-blocks and P-blocks. Additionalencoding efficiency is generally gained through this technique.

For network transmissions, the critical thing is to minimize bandwidthwhile maintaining accuracy in a reconstructed image. These two issuesare balanced by sending as many P-frames or P-blocks as possible, andsending only an occasional I-frame or I-block when it is necessary tocorrect errors. This is because I-frames and I-blocks are substantiallylarger than P-frames and P-blocks. Therefore, a typical encoder willgenerate an encoded file that consists mostly of P-frames and P-blockswith the occasional I-frame and I-block. Maximum efficiency is gained byonly ever providing one I-frame at the head of a file, and then onlyproviding a mixture of I-blocks and P-blocks to rest of the file.

However, it should be apparent from this discussion that theabove-described approach is incompatible with being able to transmit avalid image sequence file from any location within a primary videostream. This is because an image sequence decoder can only startdecoding from a complete I-frame. If there is only one I-frame in afile, and it is located at the head of the file, then that is the onlyplace in the file from which the image sequence decoder can startdecoding the file. The file must therefore be transmitted from itsbeginning, which typically results in decreased transmission efficiency.

The simplest way to correct this problem is to force the encoder toplace I-frames at periodic locations within a primary video sequence.The primary video sequence can then be decoded from any location wherean I-frame has been placed. However, this decreases the encodingefficiency.

The present invention solves this problem by maintaining a secondary bitstream of I-frames which can be used to jump into the primary bit streamfrom any location where an I-frame has been stored. This secondary bitstream of I-frames can be generated by a secondary encoder, which can beincluded in both the encoder client 14 and the transcoder client 16.This secondary bit stream is combined with the primary bit stream toproduce the first digital representation of the raw audio/video data 12and the second digital representation of the raw audio/video data 12, asdescribed above.

Referring to FIG. 2, there is shown a flowchart diagram detailing theprocessing steps of the encoder client 14. The encoder client 14processes the raw audio/video data 12, which is typically in analogform, by digitizing the raw audio/video data 12 with a digitizer 40. Thedigitized audio/video data is then encoded by a primary encoder 42,which generates a primary bit stream 44 for the first digitalrepresentation of the raw audio/video data 12 and a prediction of theprimary bit stream for the first digital representation of the rawaudio/video data 12. The prediction of the primary bit stream for thefirst digital representation of the raw audio/video data 12 isseparately encoded by a secondary encoder 45 to generate a secondary bitstream 46 for the first digital representation of the raw audio/videodata 12. The primary bit stream 44 for the first digital representationof the raw audio/video data 12 and the secondary bit stream 46 for thefirst digital representation of the raw audio/video data 12 are thencombined to form the first digital representation 48 of the rawaudio/video data 12, which is stored in the media database 22 at thelocation identified by the first URL, as described above. The primarybit stream 44 for the first digital representation of the rawaudio/video data 12 is typically in a form of an I-frame and a pluralityof P-frames, whereas the secondary bit stream 46 for the first digitalrepresentation of the raw audio/video data 12 is in the form of allI-frames. The first digital representation 48 of the raw audio/videodata 12 is typically stored in a file in the media database 22. The filetypically has a header which has pointers to the beginnings of theprimary bit stream 44 and the secondary bit stream 46 within the file.It should be noted that the primary bit stream 44 for the first digitalrepresentation of the raw audio/video data 12 and the secondary bitstream 46 for the first digital representation of the raw audio/videodata 12 must be in the same format such as, for example, JPEG, MPEG orH.263.

Referring to FIG. 3, there is shown a flowchart diagram detailing theprocessing steps of the transcoder client 16. The transcoder client 16processes the first digital representation 48 of the raw audio/videodata 12 by decoding the first digital representation 48 of the rawaudio/video data 12 with a decoder 50. The decoded audio/video data isthen encoded by a primary encoder 52, which generates a primary bitstream 54 for the second digital representation of the raw audio/videodata 12 and a prediction of the primary bit stream for the seconddigital representation of the raw audio/video data 12. The prediction ofthe primary bit stream for the second digital representation of the rawaudio/video data 12 is separately encoded by a secondary encoder 55 togenerate a secondary bit stream 56 for the second digital representationof the raw audio/video data 12. The primary bit stream 54 for the seconddigital representation of the raw audio/video data 12 and the secondarybit stream 56 for the second digital representation of the rawaudio/video data 12 are then combined to form the second digitalrepresentation 58 of the raw audio/video data 12, which is stored in themedia database 22 at the location identified by the second URL, asdescribed above. The primary bit stream 54 for the second digitalrepresentation of the raw audio/video data 12 is typically in a form ofan I-frame and a plurality of P-frames, whereas the secondary bit stream56 for the second digital representation of the raw audio/video data 12is in the form of all I-frames. The second digital representation 58 ofthe raw audio/video data 12 is typically stored in a file in the mediadatabase 22. The file typically has a header which has pointers to thebeginnings of the primary bit stream 54 and the secondary bit stream 56within the file. It should be noted that the primary bit stream 54 forthe second digital representation of the raw audio/video data 12 and thesecondary bit stream 56 for the second digital representation of the rawaudio/video data 12 must be in the same format such as, for example,JPEG, MPEG or H.263.

The primary encoder 42 in the encoder client 14 and the primary encoder52 in the transcoder client 16 can both operate according to an encodingprocess 60 such as shown in FIG. 4. This encoding process 60 comprisesdigitized audio/visual data 62, a differencing function 64, a discretecosine transform (DCT) function 66, a quantization (Q) function 68, aninverse quantization (invQ) function 70, an inverse discrete cosinetransform function (IDCT) 72, an adding function 74, a motion estimationfunction 76, a motion compensation function 78, and a delay function 80.A current frame of the digitized audio/visual data 62 is processedaccording to the encoding process 60 by differencing the current frameof the digitized audio/visual data 62 with a prediction of the currentframe at the differencing function 64. The difference between thecurrent frame of the digitized audio/visual data 62 and the predictionof the current frame is encoded by the discrete cosine transform (DCT)function 66 and the quantization (Q) function 68 to produce an encodedP-frame for a digital representation of the digitized audio/visual data62. This encoded P-frame is decoded by the inverse quantization (invQ)function 70 and the inverse discrete cosine transform function (IDCT)72, and then added to a delayed prediction of the current frame by theadding function 74. The prediction of the current frame is determined bysubjecting the output of the adding function 74 to the motion estimationfunction 76 and the motion compensation function 78. It is thisprediction of the current frame that is encoded by the secondary encoder45 in the encoder client 14 and the secondary encoder 55 in thetranscoder client 16, as described above.

At this point it should be noted that similar results can be obtained byencoding each frame of the digitized audio/visual data 62 so as toproduce the secondary bit stream 46 for the first digital representationof the raw audio/video data 12 and the secondary bit stream 56 for thesecond digital representation of the raw audio/video data 12, asdescribed above.

It should also be noted that both the secondary bit stream 46 for thefirst digital representation of the raw audio/video data 12 and thesecondary bit stream 56 for the second digital representation of the rawaudio/video data 12 could alternatively be generated at an encoderassociated with the media database server 24. For example, referring toFIG. 1B, there is shown a schematic diagram of a second embodiment of asystem 10B for organizing distributed multimedia content and forsearching, browsing, and retrieving such organized distributedmultimedia content in accordance with the present invention. The system10B is identical to the system 10A except for the addition of an encoder36, and that the encoder client 14 and the transcoder client 16 would nolonger require the secondary encoder 46 and the secondary encoder 56,respectively, as described above. The encoder 36 would generate both thesecondary bit stream 46 for the first digital representation of the rawaudio/video data 12 and the secondary bit stream 56 for the seconddigital representation of the raw audio/video data 12. That is, theencoder client 14 would generate the primary bit stream 44 as describedabove, and then transmit the primary bit stream 44 to the media databaseserver 24. The media database server 24 would then provide the primarybit stream 44 to the encoder 36, which would then generate the secondarybit stream 46. The encoder 36 would then provide the secondary bitstream 46 to the media database server 24. The media database server 24would then combine the primary bit stream 44 for the first digitalrepresentation of the raw audio/video data 12 and the secondary bitstream 46 for the first digital representation of the raw audio/videodata 12 to form the first digital representation 48 of the rawaudio/video data 12, which is then stored in the media database 22 atthe location identified by the first URL, as described above. Similarly,the transcoder client 16 would generate the primary bit stream 54 asdescribed above, and then transmit the primary bit stream 54 to themedia database server 24. The media database server 24 would thenprovide the primary bit stream 54 to the encoder 36, which would thengenerate the secondary bit stream 56. The encoder 36 would then providethe secondary bit stream 56 to the media database server 24. The mediadatabase server 24 would then combine the primary bit stream 54 for thesecond digital representation of the raw audio/video data 12 and thesecondary bit stream 56 for the second digital representation of the rawaudio/video data 12 to form the second digital representation 58 of theraw audio/video data 12, which is then stored in the media database 22at the location identified by the second URL, as described above. Theforegoing is beneficial in that only the primary bit stream 44 and theprimary bit stream 54 are transmitted from the encoder client 14 and thetranscoder client 16, respectively, to the media database server 22,which increases transmission efficiency.

It should further be noted that the primary bit streams 44 and 54 andthe secondary bit streams 46 and 56 as described above only representthe video portion of the first digital representation 48 of the rawaudio/video data 12 and the second digital representation 58 of the rawaudio/video data 12, respectively. That is, a digital representation ofan audio/video bit stream consists of three components: an audio layer,a video layer, and a system layer. The system layer tells a decoder howaudio and video are interleaved in the audio/video bit stream. Thedecoder uses this information to split the audio/video bit stream intocomponents and send each component to its appropriate decoder. On theother end, a video encoder takes a non-encoded video stream and providesan encoded video stream which is then combined with an encoded audiostream to create the three component audio/video stream. Thus, theprimary bit streams 44 and 54 and the secondary bit streams 46 and 56 asdescribed above represent video streams which will be combined withaudio streams to create three component audio/video streams.

In view of the above, it is now appropriate to indicate that the mediadatabase server 24 stores the first digital representation 48 of the rawaudio/video data 12 in the media database 22 such that each P-frame inthe primary bit stream 44 for the first digital representation of theraw audio/video data 12 references a corresponding I-frame in thesecondary bit stream 46 for the first digital representation of the rawaudio/video data 12, and vice versa. Thus, the user 11 can browse and/orretrieve a desired portion of the first digital representation 48starting at any arbitrary location within the first digitalrepresentation 48 by first obtaining an I-frame from the secondary bitstream 46 for the first digital representation of the raw audio/videodata 12 which corresponds to the arbitrary starting location of thedesired portion, and then obtaining P-frames from the primary bit stream44 for the first digital representation of the raw audio/video data 12for all subsequent locations of the desired portion. This is beneficialin that the media database server 24 will only have to send a messagecontaining a single I-frame in order for the user 11 to browse and/orretrieve a desired portion of the first digital representation 48,thereby obtaining maximum network transmission efficiency whilemaintaining the encoding advantages of only a single I-frame in theprimary bit stream 44 for the first digital representation of the rawaudio/video data 12.

Similarly, the media database server 24 stores the second digitalrepresentation 58 of the raw audio/video data 12 in the media database22 such that each P-frame in the primary bit stream 54 for the seconddigital representation of the raw audio/video data 12 references acorresponding I-frame in the secondary bit stream 56 for the seconddigital representation of the raw audio/video data 12, and vice versa.Thus, the user 11 can browse and/or retrieve a desired portion of thesecond digital representation 58 starting at any arbitrary locationwithin the second digital representation 58 by first obtaining anI-frame from the secondary bit stream 56 for the second digitalrepresentation of the raw audio/video data 12 which corresponds to thearbitrary starting location of the desired portion, and then obtainingP-frames from the primary bit stream 54 for the second digitalrepresentation of the raw audio/video data 12 for all subsequentlocations of the desired portion. This is beneficial in that the mediadatabase server 24 will only have to send a message containing a singleI-frame in order for the user 11 to browse and/or retrieve a desiredportion of the second digital representation 58, thereby obtainingmaximum network transmission efficiency while maintaining the encodingadvantages of only a single I-frame in the primary bit stream 54 for thesecond digital representation of the raw audio/video data 12.

Referring to FIG. 5, there is shown a file structure for a file 90 thatis stored in the media database 22 containing either the first digitalrepresentation 48 of the raw audio/video data 12 or the second digitalrepresentation 58 of the raw audio/video data 12. The file 90 comprisesa header portion 92, a primary bit stream portion 94, and a secondarybit stream portion 96. The header portion 92 comprises a file identifier98 for either the first digital representation 48 of the raw audio/videodata 12 or the second digital representation 58 of the raw audio/videodata 12, a pointer 100 to the beginning of the primary bit streamportion 94, and a pointer 102 to the beginning of the secondary bitstream portion 96. The primary bit stream portion 94 comprises anI-frame 104 and a plurality of P-frames 106. The secondary bit streamportion 96 comprises a plurality of I-frames 108. The references betweenthe P-frames 106 in the primary bit stream portion 94 and the I-frames108 in the secondary bit stream portion 96, and vice versa, can beincluded in the P-frames 106 in the primary bit stream portion 94 andthe I-frames 108 in the secondary bit stream portion 96. Alternatively,the header portion 92 can include additional pointers to correspondingP-frames 106 in the primary bit stream portion 94 and I-frames 108 inthe secondary bit stream portion 96.

As previously described, the annotation client 18 processes the copy ofthe first digital representation of the raw audio/video data 12 suchthat annotations are generated for the object in the meta database 26corresponding to the raw audio/video data 12. The librarian 28 thenstores these annotations in the meta database 26 along with the objectidentification number associated with the raw audio/video data 12. Theimplementation of these steps in accordance with the present inventionis directly related to annotation processes and the structure of themeta database 26.

Annotations are generated for an object so as to provide informationabout the whole object or a part of the object. Annotations may begenerated for an object by trusted automatic processes called annotationdaemons, such as the annotation client 18, or by trusted humanannotators. Annotations which have previously been generated for anobject, including both annotations produced by annotation daemons or byhuman annotators, may be reviewed and updated.

Annotations in accordance with the present invention are a typed,probabilistic, stratified collection of values. Referring to FIG. 6,there is shown an annotation structure 110 for an object in accordancewith the present invention. The annotation structure 110 comprises afirst annotation sequence 114 and a second annotation sequence 116. Thefirst annotation sequence 114 and the second annotation sequence 116relate to a media stream 112, which can be either an audio or a videostream. Each annotation sequence represents a different type ofannotation such as, for example, words that occur in the media stream112 or speakers that are recognized in the media stream 112.

Each annotation sequence contains a plurality of time marks 117 and aplurality of arcs 118. Each time mark 117 represents an instant in time.Each arc 118 represents an interval of time. Each arc 118 also has anassociated value and probability. The probability is a measure ofconfidence in the accuracy of the annotation. The use of a probabilityallows probabilistic-based retrieval to be supported. The use of aprobability also allows the quality (e.g., higher or lower quality) of areplacement annotation to be determined. Each annotation sequence can beapplied to the entire media stream 112 or to a part thereof.

The annotation structure 110 as described above differs from many videoannotation systems that work on shot lists. In this prior art approach,a video is first broken down into thematic chunks called shots that arethen grouped into scenes. Each shot is then taken as a basic atomic unitfor annotation. That is, each shot is annotated, and searching will onlyretrieve particular shots. The difficulty of this prior approach is thatperforming the above processing automatically can be very difficult. Thepresent invention avoids this difficulty by allowing the presence ofpeople and things to be marked within a scene.

The structure of the meta database 26 is such that it is an objectdatabase built on top of standard relational databases. Each object inthe object database of the meta database 26 represents some form ofaudio/video data such as, for example, the raw audio/video data 12, asdescribed above. For every object in the object database of the metadatabase 26 there can be one or more representations and/or annotations.A representation of an object in the object database of the metadatabase 26 can be a representation of the audio/video data that isrepresented by the object in the object database of the meta database 26such as, for example, the first digital representation of the rawaudio/video data 12, as described above. An annotation of an object inthe object database of the meta database 26 can be an annotation that isgenerated by processing one or more representations of the audio/videodata that is represented by the object in the object database of themeta database 26 such as, for example, an annotation that was generatedby processing the copy of the first digital representation of the rawaudio/video data 12, as described above.

The structure of an object database 120 of the meta database 26 inaccordance with the present invention is shown in FIG. 7. The objectdatabase 120 comprises an object 122, a plurality of representations 124of the object 122, and a plurality of annotations 126 of the object 122.As indicated by the direction of the arrows, each of the plurality ofrepresentations 124 of the object 122 reference the object 122, and eachof the plurality of annotations 126 of the object 122 reference theobject 122. It should be noted that an annotation 126 may reference morethan one object 122, indicating that the annotation 126 is shared by themore than one object 122.

All of the objects in the object database of the meta database 26 arelisted in an object table 130 of the meta database 26, as shown in FIG.8. Each of the objects in the object database of the meta database 26are assigned an object identification number 132, as previouslydescribed. Each object identification number 132 is unique and istypically in numeric or alphanumeric form, although other forms are alsopermitted. Each of the objects in the object database of the metadatabase 26 are typically listed in the object table 130 according tothe value of their object identification numbers 132, as shown.

Each of the objects in the object database of the meta database 26 arealso assigned an object type 134. The object type 134 can be, forexample, video or audio, corresponding to the type of data that isrepresented by the object in the object database of the meta database26. Accordingly, each of the objects in the object database of the metadatabase 26 are listed in the object table 130 with a correspondingobject type 134.

All of the representations in the object database of the meta database26 are listed in a representation table 140 of the meta database 26, asshown in FIG. 9. Each of the representations in the object database ofthe meta database 26 are assigned a representation identification number142. Similar to the object identification numbers 132, eachrepresentation identification number 142 is unique and is typically innumeric or alphanumeric form, although other forms are also permitted.Each of the representations in the object database of the meta database26 are typically listed in the representation table 140 according to thevalue of their representation identification numbers 142, as shown.

As previously discussed, each of the representations in the objectdatabase of the meta database 26 is associated with an object in theobject database of the meta database 26. Accordingly, each of therepresentations in the object database of the meta database 26 arelisted in the representation table 140 with an associated objectidentification number 132.

Each of the representations in the object database of the meta database26 are also assigned a representation type 144. The representation type144 can be, for example, video/mpeg, video/x-realvideo, audio/mpeg, oraudio/x-realvideo, corresponding to the format type of therepresentation in the object database of the meta database 26.Accordingly, each of the representations in the object database of themeta database 26 are listed in the representation table 140 with acorresponding representation type 144.

As previously discussed, each of the representations in the objectdatabase of the meta database 26 have an associated URL which identifiesthe location in the media database 22 where the representation can befound. Accordingly, each of the representations in the object databaseof the meta database 26 are listed in the representation table 140 withan associated URL 146.

All of the annotations in the object database of the meta database 26are listed in an annotation table 150 of the meta database 26, as shownin FIG. 10. Each of the annotations in the object database of the metadatabase 26 are assigned an annotation identification number 152.Similar to the object identification numbers 132 and the representationidentification numbers 142, each annotation identification number 152 isunique and is typically in numeric or alphanumeric form, although otherforms are also permitted. Each of the annotations in the object databaseof the meta database 26 are typically listed in the annotation table 150according to the value of their annotation identification numbers 152,as shown.

As previously discussed, each of the annotations in the object databaseof the meta database 26 are associated with an object in the objectdatabase of the meta database 26. Accordingly, each of the annotationsin the object database of the meta database 26 are listed in theannotation table 150 with an associated object identification number132.

Each of the annotations in the object database of the meta database 26are also assigned an annotation type 154. The annotation type 154 canbe, for example, transcript, speaker, or keyframe. Each annotation type154 corresponds to the type of annotation that has been generated for acorresponding object in the object database of the meta database 26.Accordingly, each of the annotations in the object database of the metadatabase 26 are listed in the annotation table 150 with a correspondingannotation type 154.

Each of the annotations in the object database of the meta database 26have a corresponding annotation value 156. The annotation value 156 canbe, for example, a word, the name of a speaker, or an URL whichreferences an image in the media database 22. Each annotation value 156corresponds to the actual annotated element of the object in the objectdatabase of the meta database 26. Accordingly, each of the annotationsin the object database of the meta database 26 are listed in theannotation table 150 with a corresponding annotation value 156.

Annotations which have been generated for an object that represents anaudio/video stream have a corresponding annotation start time 158 and acorresponding annotation end time 160. The annotation start time 158corresponds to the location in the audio/video stream where anannotation actually begins. Conversely, the annotation end time 160corresponds to the location in the audio/video stream where anannotation actually ends. Accordingly, each of the annotations in theobject database of the meta database 26 which have been generated for anobject that represents an audio/video stream are listed in theannotation table 150 with a corresponding annotation start time 158 anda corresponding annotation end time 160.

As previously described, the index database server 32 stores theannotations that were generated for the object in the meta database 26corresponding to the raw audio/video data 12 in the index database 30along with, or with reference there to, the object identification numberassociated with the raw audio/video data 12. The index database server32 then searches the index database 30 for annotations which match aquery initiated by the user 11, and then obtains the objectidentification number associated with each matching annotation. Theimplementation of these steps in accordance with the present inventionis directly related to the indexing process and the structure of theindex database 30.

The index database server 32 stores the annotations in the indexdatabase 30 such that an entry is created in the index database 30 foreach annotation value. Following each annotation value entry in theindex database 30 is a list of start times for each occurrence of theannotation value within an associated object. The start times can belisted according to actual time of occurrence in the associated objector in delta value form. Following the list of start times for eachoccurrence of the annotation value within the associated object is theobject identification number corresponding to the associated object, ora reference to such object identification number. Thus, each of theseannotation value entries in the index database 30 is linked in somemanner to the start times for each occurrence of the annotation valuewithin an associated object and the object identification numbercorresponding to the associated object. Therefore, whenever the indexdatabase server 32 searches the index database 30 for annotation valueswhich match a query, the start times for each occurrence of a matchingannotation value within an associated object and the objectidentification number corresponding to the associated object can beeasily obtained.

Once the index database server 32 has a matching annotation value, thestart times for each occurrence of the matching annotation value withinan associated object, and the object identification number correspondingto the associated object, the index database server 32 can send amessage, including the matching annotation value, the start times foreach occurrence of the matching annotation value within an associatedobject, and the object identification number corresponding to theassociated object, over the communication network 34 to the librarian 28requesting that the librarian 28 provide further information relating tothe matching annotation value and the associated object identificationnumber. Such information can include the annotation type, the annotationstart time, the annotation end time, the representation type, the URL,and the object type associated with the matching annotation value andthe associated object identification number, all of which have beendescribed above. In short, the librarian 28 provides everything that theindex database server 32 requires to build an HTML results page forpresentation to the user 11.

At this point it should be noted that the start times for eachoccurrence of a matching annotation value within an associated objectare included in the message from the index database server 32 to thelibrarian 28 so as to make searching the meta database 26 moreefficient. That is, searching the meta database 26 for numerical valuestypically requires less processing than searching the meta database 26for textual values. Also, a matching annotation value and the starttimes for each occurrence of a matching annotation value within anassociated object are directly related. However, a matching annotationvalue is typically a textual value, whereas the start times for eachoccurrence of a matching annotation value within an associated objectare numerical values. Thus, using the start times for each occurrence ofa matching annotation value within an associated object to search themeta database 26 for information is more efficient than using a matchingannotation value.

At this point it should be noted that the index database server 32inherently knows that it must look to the librarian 28 to providefurther information relating to the matching annotation value and theassociated object identification number. That is, it is inherent to theindex database server 32 that a request for further information relatingto the matching annotation value and the associated objectidentification number must be sent to the librarian 28.

In view of the above, the operation of both the system 10A and system10B can now be described in more detail. That is, system 10A and system10B both operate such that subsequent to a request from the encoderclient 14, the librarian 28 creates an object in the meta database 26,and stores information in the meta database 26 along with the object.This information includes the URL of a digital representation of mediadata, the form of the digital representation of the media data, the type(e.g., audio, video, etc.) of the form of the digital representation ofthe media data, the format in which the digital representation of themedia data is stored at the URL, the URL and types of any ancillaryfiles associated with the media data such as a transcript orclosed-caption file, and any associated high-level meta data such as thetitle of the media data and/or its author.

After the object has been created, the annotation client 18 can requestwork from the librarian 28 and process digital representations which thelibrarian 28 has indicated have not already been processed by theannotation client 18, as previously described. The annotation client 18employs an automatic process, called a daemon process, to perform theannotation function. Automatic daemon processes are preferred over humanannotation processes, which can be a very laborious. However, automaticdaemon processes which produce high quality results, appropriatelytermed trusted daemon processes, are sometimes hard to come by given thecurrent state of technology. Thus, it is important to provide aflexible, distributed, open architecture which can be used toincorporate new approaches to automatic annotation. The presentinvention achieves this by allowing each annotation client 18 tocommunicate with the librarian 28 and the media database server 24 overthe communication network 34 using a standard messaging protocol (e.g.,HTTP messaging).

The annotation client 18 requests work from the librarian 28 byproviding two boolean conditions, an identifier of the annotation client18, a version number of the annotation client 18, and an estimate of howlong the annotation client 18 will take to complete the work (i.e., theannotation process). The first boolean condition is used to test for theexistence of an object which satisfies the input requirements of thedaemon process. That is, if an object satisfies the condition, then theinputs necessary for the daemon process to run exist and are referencedin the meta database 26. The second boolean condition tests for thenon-existence of the output produced by the daemon process. If theseboolean conditions are satisfied, then the daemon process should be runon the object.

The librarian 28 provides work to the annotation client 18 by firstcreating a list containing all objects which satisfy both booleanconditions. The librarian 28 then filters the list by eliminatingobjects which are presently being processed, or locked, by anotherannotation client 18 having the same identifier and version number. Thelibrarian 28 then creates a key for each object remaining on the listwhich identifies the annotation client 18 and includes an estimate ofhow long the annotation client 18 will take to complete the work. Thiskey is used to lock out other annotation clients, as described above.The librarian 28 then provides the URL of each digital representationremaining on the list to the annotation client 18 for processing, aspreviously described.

The annotation client 18 uses the returned work information to performits operations. That is, the annotation client 18 uses the URL of eachdigital representation to request each digital representation from themedia database server 22, as previously described. The annotation client18 then performs its work.

Upon completion of its work, the annotation client 18 checks its workinto the librarian 28 for storage in the meta database 26. Theannotation client 18 accomplishes this task by returning the objectidentification number associated with the object, the newly generatedannotation data, and the key to the librarian 28. The librarian 28checks the key to make sure that it matches the key in A space reservedfor the completed operation. If the annotation client 18 returns thecorrect key, and the estimated work completion time has not expired, thekey will match and the librarian 28 will accept the complete result.However, if the estimated work completion time has expired, the key mayalso have expired if another annotation client 18, having the sameidentifier and version number, requested work after the estimated workcompletion time had expired. If this is the case, the work will havebeen given to the new requesting annotation client 18, and a new keywill have been generated. Therefore, the first requesting annotationclient 18 will not be able to check in its work.

The aforementioned protocol permits completely distributed processing ofinformation with very low communications overhead. Also, the use of URLsmakes it possible for the processing to occur anywhere on the network,although only privileged addresses (i.e., those belonging to trustedannotation clients 18) may install results in the librarian 28.Furthermore, the simple time stamp protocol makes the system tolerant toprocessing failures.

It is also possible to directly select an object to be worked on. Thisallows a human to force an order of work. This is useful for humanreview of annotations produced by automatic daemon processes. From thepoint of view of the librarian 28, a human sitting at an annotationstation is just another requesting annotation client 18. However, thehuman will want to request work that has already been completed by anautomatic daemon process by specifically searching for items and thenlocking those items with a key. When a human reviews the work, theprobabilities of the annotation can be updated to nearly 1 because theannotations were reviewed via a manual process. When the work is checkedin, the librarian 28 will check that the new annotations are of higherquality than the old annotations by looking at the probabilitiesassociated with each annotation.

Some of the key features of the above-described approach are that theannotation clients 18 can request work via an independent action(although they must be trusted), that there is a simple lockingmechanism to prevent annotation clients 18 from stepping on each other,that annotation clients 18 provide new annotation information based ontransformations of the original object, that new types of annotationclients 18 can be added in a straightforward manner, that there aremeans for updating the results of annotation clients 18 (e.g., byversion number), and that there are means for comparing the results ofannotation clients 18 based on source (e.g., based on probability).

The index database server 32 indexes the meta database 26 byperiodically requesting from the librarian 28 a list of objectidentification numbers which correspond to objects that have beencreated in the meta database 26. In response, the librarian 28 providesa list of object identification numbers which correspond to objects thathave been created in the meta database 26 to the index database server32. The index database server 32 then requests from the librarian 28,for each object identification number, a copy of all of the annotationsthat were generated for each object in the meta database 26. Inresponse, the librarian 28 provides, for each object identificationnumber,-a copy of all of the annotations that were generated for eachobject in the meta database 26 to the index database server 32. Theindex database server 32 then stores the annotations that were generatedfor each object in the meta database 26 in the index database 30 alongwith, or with reference to, each associated object identificationnumber.

As previously described, the browser client 20 sends a message,initiated by the user 11, to the index database server 32 requesting asearch of the index database 30. In response, the index database server32 provides an HTML query page to the browser client 20 for presentationto the user 11. The browser client 20 then presents the HTML query pageto the user 11. Referring to FIG. 11, there is shown an exemplary HTMLquery page 170 including a search field 172, a user-selectable searchcommand 174, a user-selectable “help” option 176, and a user-selectable“advanced search” option 178.

The user 11 enters a query through the HTML query page and the browserclient 20 sends a message, including the query, to the index databaseserver 32 for processing by the index database server 32. In response,the index database server 32 searches the index database 30 forannotation values which match the query. Once the index database server32 has found matching annotation values, the index database server 32ranks the matching annotation values according to relevance, and obtainsthe object identification number associated with each matchingannotation value. The index database server 32 then requests thelibrarian 28 to provide further information relating to each matchingannotation value by referencing each associated object identificationnumber. As previously described, such information can include theannotation type, the annotation start time, the annotation end time, therepresentation type, the URL, and the object type associated with eachmatching annotation value and the associated object identificationnumber. The librarian 28 then sends the requested information to theindex database server 32.

At this point it should be noted that the index database server 32 ranksthe matching annotation values using a modified document retrievaltechnique. The unmodified document retrieval technique uses a documentas a basic unit, and determines the importance of a document based upona query. That is, the importance of a document is based on the number ofoccurrences of each query word within the document, with each query wordbeing weighted by the rarity of the query word in a document database.Thus, more rare words are given higher weights than common words, anddocuments with more query words receive higher total weights thandocuments with fewer query words. A typical equation for computing thescore of a document is

score(d)=sum_{q}w[q]  (1)

wherein d is a document, q is a query word, sum_{q} is the number oftimes that the query word q appears in the document d, and w[q] is theweight of the query word q. It should be clear that the above-describedtechnique requires using all of the words in a document for determiningthe weight of the document.

In audio/video retrieval, it is a requirement that users be able tostart an audio/video stream from the most relevant position within theaudio/visual stream. Thus, an indexing system must not only determinethat an audio/video stream is relevant, but also all relevant locationswithin the audio/video stream, and preferably rank the relevance ofthose locations.

The present invention modifies the above-described technique by lettingh[i] be a valid starting location within an audio/video stream, andletting L[q,j] be the jth location of the query word q in theaudio/video stream. Then the score at valid starting location h[i] canbe given by

score(h[i])=sum_(—) {L[q,j]>=h[i]}w[q]exp(−(L[q,j]−h[i])/DELTA)  (2)

wherein DELTA is a setable distance weight equal to 10-30 seconds. Thus,the score at a valid starting location is a weighted sum over all thelocations the query word appears after the valid starting location,where the weight of each appearance of a query word is the product ofthe query word weight and a negative exponential weight on the distancebetween the occurrence of the query word and the query word in time.This modified ranking technique provides a unique advantage to the indexdatabase server 32 of the present invention.

The index database server 32 uses the information provided by thelibrarian 28 to build an HTML results page for presentation to the user11. The index database server 32 builds the HTML results page bycreating an image or an icon for each matching annotation value. Eachimage or icon is hyperlinked to a function or script which allows theuser 11 to browse and/or retrieve all or a portion of a correspondingdigital representation. Once the HTML results page has been built, theindex database server 32 sends the HTML results page to the browserclient 20 for presentation to the user 11. The browser client 20 thenpresents the HTML results page to the user 11 so that the user 11 canselect one of the images or icons so as to browse and/or retrieve all ora portion of a corresponding digital representation.

Referring to FIG. 12, there is shown an exemplary HTML results page 190for a query which included the terms “commission” and “history”. TheHTML results page 190 includes an almost exact copy of the HTML querypage 192 containing a statement as to the number of matches that werefound for the query, which in this case is five. The HTML results page190 also includes either a video icon 194 or an audio icon 196 dependingupon the type of object that is associated with each matching annotationvalue. Both the video icon 194 and the audio icon 196 are provided alongwith some detail about each associated object. For example, in the caseof a video icon 194, the title of the corresponding video stream, aframe of the corresponding video stream, a textual excerpt from thecorresponding video stream, the length of the corresponding videostream, the language that is spoken in the corresponding video stream,and the number of matches that occur within the corresponding videostream are shown or listed along with the video icon 194. In the case ofan audio icon 196, the title of the corresponding audio stream, atextual excerpt from the corresponding audio stream, the length of thecorresponding audio stream, the language that is spoken in thecorresponding audio stream, and the number of matches that occur withinthe corresponding audio stream are listed along with the audio icon 196.

If the user 11 selects either a video icon 194 or an audio icon 196,then the video or audio stream will play from the location of the firstmatch within the corresponding video or audio stream. This is possiblebecause both the video icon 194 and the audio icon 196 are hyperlinkedback to a function or script in the index database server 32, wherebythe index database server 32 uses the information provided by thelibrarian 28 to access a corresponding digital representation in themedia database 22 using the extended URL format described above. If morethan one match occurs within either a video or an audio stream, then auser-selectable “matches” option 198 is provided to allow the user 11browse each location within the video or audio stream where a match hasoccurred, as described in more detail below. If the user 11 desires tobrowse locations surrounding the location of the first match within thecorresponding video or audio stream, then a user-selectable “morecontext” option 200 is provided to allow the user 11 browse locationssurrounding the location of the first match within the correspondingvideo or audio stream, as described in more detail below.

To illustrate the above-described “matches” option 198, it is assumedthat the user 11 has selected the “matches” option 198 associated withthe third match presented in the HTML results page 190 (i.e., the videoentitled, 1998 State of the Union Address). Referring to FIG. 13, thereis shown an exemplary HTML matches page 210 for allowing the user 11 tobrowse each location within the video stream associated with the thirdmatch presented in the HTML results page 190 where a match has occurred.The HTML matches page 210 includes an almost exact copy of the HTMLquery page 212, which contains an additional user-selectable “searchthis result” option 214 for allowing the user 11 to refine the resultsof a previous query. The HTML matches page 210 also includes a matchesheader 216 containing the title of the corresponding video stream, thelength of the corresponding video stream, the language that is spoken inthe corresponding video stream, and the number of matches that occurwithin the corresponding video stream, which in this case is four. TheHTML matches page 210 further includes a frame 218 which corresponds toeach match that occurs within the corresponding video stream. Each frame218 includes a video icon 220, which functions in a manner similar tothe previously-described video icon 194. Each frame 218 andcorresponding video icon 220 are provided along with some detail abouteach associated match that occurs within the corresponding video stream.For example, the exact time location of the match within thecorresponding video stream and a textual excerpt from the correspondingvideo stream are listed along with each frame 218 and correspondingvideo icon 220. Similar to the HTML results page 190, the HTML matchespage 210 includes a user-selectable “more context” option 222 for eachmatch to allow the user 11 browse locations surrounding the location ofeach associated match within the corresponding video stream.

To illustrate the above-described “more context” options 200 and 222, itis assumed that the user 11 has selected the “more context” option 222associated with the first match presented in the HTML matches page 210.Referring to FIG. 14, there is shown an exemplary HTML more context page230 for allowing the user 11 to browse locations surrounding thelocation of the first match presented in the HTML matches page 210within the corresponding video stream. The HTML more context page 230includes an almost exact copy of the HTML query page 232, which containsan additional user-selectable “search this result” option 234 forallowing the user 11 to refine the results of a previous query. The HTMLmore context page 230 also includes a more context header 236 containingthe title of the corresponding video stream, the length of thecorresponding video stream, and the language that is spoken in thecorresponding video stream. The HTML more context page 230 furtherincludes a frame 238 which corresponds to an actual frame within thecorresponding video stream. Each frame 238 includes a video icon 240,which functions in a manner similar to the previously-described videoicons 194 and 220. Each frame 238 and corresponding video icon 240 areprovided along with some detail about each associated frame 238 withinthe corresponding video stream. For example, the exact time location ofthe frame 238 within the corresponding video stream and a textualexcerpt from the corresponding video stream are listed along with eachframe 238 and corresponding video icon 240. The HTML more context page230 still further includes a user-selectable “backward” option 242 and auser-selectable “forward” option 244 for allowing the user 11 to browsefurther locations surrounding the location of the first match presentedin the HTML matches page 210 within the corresponding video stream.

Lastly, it should be noted that the encoder client 14, the transcoderclient 16, the annotation client 18, the browser client 20, the mediadatabase server 24, the librarian 28, the index database server 32, andthe encoder 36 all involve the processing of input data and thegeneration of output data to some extent. The processing of the inputdata and the generation of the output data are preferably implemented bysoftware programs. Thus, referring to FIG. 15, each of theabove-described system components preferably comprises a processingdevice 250 including at least one processor (P) 252, memory (M) 254, andinput/output (I/O) interface 256, connected to each other by a bus 258,for facilitating the implementation of input data processing and outputdata generation in each of the above-described system components.

The present invention is not to be limited in scope by the specificembodiments described herein. Indeed, various modifications of thepresent invention, in addition to those described herein, will beapparent to those of skill in the art from the foregoing description andaccompanying drawings. Thus, such modifications are intended to fallwithin the scope of the appended claims.

What is claimed is:
 1. A method for matching a query to a portion ofmedia, comprising the steps of: receiving a query relating to media ofinterest; searching, based upon the query, a plurality of annotationvalues to identify an annotation value within the plurality ofannotation values which matches the query, each of the plurality ofannotation values corresponding to a respective portion of a respectiveitem of available media; identifying a start time of a media streamforming a first portion of a first item of available media correspondingto the identified annotation value; and providing the identified mediastream start time in response to the query.
 2. A method as recited inclaim 1, further comprising the step of; identifying an end time of themedia stream; and providing the identified media stream end time inresponse to the query.
 3. A method as recited in claim 2, wherein theend time is identified by a delta value.
 4. A method as recited in claim1, further comprising the step of: searching, based upon the identifiedmedia stream start time, a meta database having a plurality of starttimes to identify a start time within the plurality of start times whichmatches the identified media stream start time, each of the plurality ofstart times having an associated end time; identifying the end timeassociated with the identified matching start time as an end time of themedia stream; and providing the identified media stream end time inresponse to the query.
 5. A method as recited in claim 1, furthercomprising the steps of: searching, based upon the identified mediastream start time, a meta database having a plurality of start times toidentify a start time within the plurality of start times which matchesthe identified media stream start time, each of the plurality of starttimes having an associated address of a respective item of availablemedia; identifying the item address associated with the identifiedmatching start time as an address of the first item of available media;and providing the identified address in response to the query.
 6. Amethod as recited in claim 5, wherein the identified address is a URL.7. A method as recited in claim 6, wherein the identified media streamstart time is provided as an extension of the URL.
 8. A method asrecited in claim 1, wherein each of the plurality of annotation valuescorresponds to at least one respective portion of at least onerespective item of available media, further comprising the steps of:identifying at least one other start time of at least one other mediastream forming at least one other respective portion of at least oneother respective item of available media corresponding to the identifiedannotation value; and providing the at least one other identified mediastream start time in response to the query.
 9. A method as recited inclaim 1, wherein the plurality of annotation values includes text.
 10. Amethod as recited in claim 1, wherein the plurality of annotation valuesinclude a plurality of words.
 11. A method as recited in claim 1,wherein each respective item of available media includes one of audiomedia and video media.
 12. A system for matching a query to a portion ofmedia, comprising: a memory configured to store a plurality ofannotation values, each of the plurality of annotation values beingassociated with a start time of a media stream forming a respectiveportion of a respective item of available media; and a processorconfigured to search the stored plurality of annotation values to matcha query relating to media of interest to an annotation value within thestored plurality of annotation values and thereby identify the starttime associated with the matched annotation value, and to respond to thequery using the identified start time.
 13. A system as recited in claim12, wherein the processor is a first processor and further comprising: ameta database having a plurality of start times, each of the pluralityof start times having an associated end time; and a second processorconfigured to search the meta database to match the identified starttime to a start time within the plurality of start times and therebyidentify the end time associated with the matched annotation value, andto direct the identified end time to the first processor; wherein thefirst processor is further configured to respond to the query using theidentified end time.
 14. A system as recited in claim 12, wherein theprocessor is a first processor and further comprising: a meta databasehaving a plurality of start times, each of the plurality of start timeshaving an associated address of a respective item of available media;and a second processor configured to search the meta database to matchthe identified start time to a start time within the plurality of starttimes and thereby identify the item address associated with the matchedannotation value, and to direct the identified item address to the firstprocessor; wherein the first processor is further configured to respondto the query using the identified item address.
 15. A system as recitedin claim 14, wherein the identified item address is a URL.
 16. A systemas recited in claim 15, wherein the identified start time is anextension of the URL.
 17. A system as recited in claim 12, wherein: eachof the plurality of annotation values corresponds to at least onerespective portion of at least one respective item of available media;and the processor is further configured to identify at least one otherstart time of at least one other media stream forming at least one otherrespective portion of at least one other respective item of availablemedia corresponding to the matched annotation value by matching thequery to the matched annotation value, and to respond to the query usingthe at least one other identified start time.
 18. A system as recited inclaim 12, wherein the plurality of annotation values include text.
 19. Asystem as recited in claim 12, wherein the plurality of annotationvalues include a plurality of words.
 20. A system as recited in claim12, wherein each item of available media includes one of audio media andvideo media.
 21. An article of manufacture for matching a query to aportion of media, the article of manufacture comprising: a computerreadable storage media; and computer programming stored on the storagemedia; wherein the stored computer programming is configured to bereadable from the computer readable storage medium by one or morecomputers and thereby cause the one or more computers to operate so asto: search a plurality of annotation values, each corresponding to arespective portion of a respective item of available media, to match aquery relating to media of interest to an annotation value within theplurality of annotation values and thereby identify a start time of amedia stream forming a first portion of a first item of available mediacorresponding to the matched annotation value; and generate a signalrepresenting the identified media stream start time in response to thequery.
 22. An article of manufacture as recited in claim 21, wherein thestored computer programming is further configured to be readable by theone or more computers to thereby cause the one or more computers tooperate so as to: search a meta database having a plurality of starttimes, each having an associated address of a respective item ofavailable media, to match the identified media stream start time with astart time within the plurality of start times and thereby identify theitem address associated with the matched annotation value; and generatea signal representing the identified address in response to the query.23. An article of manufacture as recited in claim 21, wherein theidentified address is a URL.
 24. An article of manufacture as recited inclaim 23, wherein the identified media stream start time is provided asan extension of the URL.
 25. An article of manufacture as recited inclaim 21, wherein each of the plurality of annotation values correspondsto at least one respective portion of at least one respective item ofavailable media, and the stored computer programming is furtherconfigured to be readable by the one or more computers to thereby causethe one or more computers to operate so as to: identify at least oneother start time of at least one other media stream forming at least oneother respective portion of at least one respective item of availablemedia corresponding to the matched annotation value; and generate asignal representing the at least one other identified media stream starttime in response to the query.